Question

Срочно, 98 баллов помогите крч по алгебре

Answer 1

$1) frac{ {m}^{2} - {n}^{2} }{m - n} \ \ frac{ {2.5}^{2} - ({ - 7.5)}^{2} }{2.5 - ( - 7.5)} = frac{ frac{25}{4} - ( - frac{ {15}^{2} }{4} ) }{10} = frac{25 - {15}^{2} }{4} = - 5$

$2) frac{1}{4x} - frac{4x + y}{4xy} = frac{y - (4x + y)}{4xy} = \ \ = - frac{4x}{4xy} = - frac{1}{y} \ \ - frac{1}{ frac{1}{2} } = - 2$

$3)(x - 3) div frac{ {x}^{2} - 6x + 9}{x + 3} = (x - 3) times frac{x + 3}{ {x}^{2} - 6x + 9 } = \ \ = frac{(x - 3)(x + 3)}{(x - 3)^{2} } = frac{x + 3}{x - 3}$

$4)16 times {2}^{ - 5} times {2}^{6} = {2}^{4} times {2}^{ - 5} times {2}^{6} = \ = {2}^{4 - 5 + 6} = {2}^{5} = 32$

$5)3 sqrt{2} + sqrt{50} - 2 sqrt{8} = 3 sqrt{2} + 5 sqrt{2} - 4 sqrt{2} = 4 sqrt{2}$

$6) frac{49 - {a}^{2} }{a - 9} ( frac{a}{a - 7} - frac{2a}{ {a}^{2} - 14a + 49} ) + frac{14a}{a - 7} = \ \ = frac{(7 - a)(7 + a)}{a - 9} - frac{a times (a - 7) - 2a}{ {(a - 7)}^{2} } + frac{14a}{a - 7} = \ \ = frac{ - (7 + a)}{a - 9} - frac{ {a}^{2} - 9a }{a - 7} + frac{14a}{a - 7} = \ \ = - frac{7a + {a}^{2} }{a - 7} + frac{14a}{a - 7} = \ \ = frac{ - 7a - {a}^{2} + 14a }{a - 7} = frac{7a - {a}^{2} }{a - 7} = frac{ - (a - 7) times a}{a - 7} = \ \ = - a$

Answer 2

Большое спасибо